From: Gustavo Padovan gustavo.padovan@collabora.co.uk

We don't use the 'fence' name to refer to sync_file anymore. So rename it to SYNC_IOC_FILE_INFO.

Signed-off-by: Gustavo Padovan gustavo.padovan@collabora.co.uk Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com --- drivers/staging/android/sync.c | 2 +- drivers/staging/android/uapi/sync.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index 31aa462..dc5f382 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -562,7 +562,7 @@ static long sync_file_ioctl(struct file *file, unsigned int cmd, case SYNC_IOC_MERGE: return sync_file_ioctl_merge(sync_file, arg);

- case SYNC_IOC_FENCE_INFO: + case SYNC_IOC_FILE_INFO: return sync_file_ioctl_fence_info(sync_file, arg);

default: diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h index 4ffb7cc..dd0dd84 100644 --- a/drivers/staging/android/uapi/sync.h +++ b/drivers/staging/android/uapi/sync.h @@ -81,6 +81,6 @@ struct sync_file_info { * pt_info is a buffer containing sync_pt_infos for every sync_pt in the fence. * To iterate over the sync_pt_infos, use the sync_pt_info.len field. */ -#define SYNC_IOC_FENCE_INFO _IOWR(SYNC_IOC_MAGIC, 2, struct sync_file_info) +#define SYNC_IOC_FILE_INFO _IOWR(SYNC_IOC_MAGIC, 2, struct sync_file_info)

#endif /* _UAPI_LINUX_SYNC_H */

From: Gustavo Padovan gustavo.padovan@collabora.co.uk

Change SYNC_IOC_FILE_INFO behaviour to avoid future API breaks and optimize buffer

Now num_fences can be filled by the caller to inform how many fences it wants to retrieve from the kernel. If the num_fences passed is greater than zero info->sync_fence_info should point to a buffer with enough space to fit all fences.

However if num_fences passed to the kernel is 0, the kernel will reply with number of fences of the sync_file.

Sending first an ioctl with num_fences = 0 can optimize buffer allocation, in a first call with num_fences = 0 userspace will receive the actual number of fences in the num_fences filed.

Then it can allocate a buffer with the correct size on sync_fence_info and call SYNC_IOC_FILE_INFO again, but now with the actual value of num_fences in the sync_file.

Also, info->sync_fence_info was converted to __u64 pointer to prevent 32bit compatibility issues.

An example userspace code for the later would be:

struct sync_file_info *info; int err, size, num_fences;

info = malloc(sizeof(*info));

info.flags = 0; err = ioctl(fd, SYNC_IOC_FILE_INFO, info); num_fences = info->num_fences;

if (num_fences) { info.flags = 0; size = sizeof(struct sync_fence_info) * num_fences; info->num_fences = num_fences; info->sync_fence_info = (uint64_t) calloc(num_fences, sizeof(struct sync_fence_info));

err = ioctl(fd, SYNC_IOC_FILE_INFO, info); }

Signed-off-by: Gustavo Padovan gustavo.padovan@collabora.co.uk Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com --- v2: fix fence_info memory leak

v3: Comments from Emil Velikov - improve commit message - remove __u64 cast - remove check for output fields in file_info - clean up sync_fill_fence_info()

Comments from Maarten Lankhorst - remove in.num_fences && !in.sync_fence_info check - remove info->len and use only num_fences to calculate size

Comments from Dan Carpenter - fix info->sync_fence_info documentation

v4: remove allocated struct sync_file_info (comment from Maarten) --- drivers/staging/android/sync.c | 70 +++++++++++++++++-------------------- drivers/staging/android/uapi/sync.h | 9 ++--- 2 files changed, 36 insertions(+), 43 deletions(-)

diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index dc5f382..48ee175 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -479,13 +479,9 @@ err_put_fd: return err; }

-static int sync_fill_fence_info(struct fence *fence, void *data, int size) +static void sync_fill_fence_info(struct fence *fence, + struct sync_fence_info *info) { - struct sync_fence_info *info = data; - - if (size < sizeof(*info)) - return -ENOMEM; - strlcpy(info->obj_name, fence->ops->get_timeline_name(fence), sizeof(info->obj_name)); strlcpy(info->driver_name, fence->ops->get_driver_name(fence), @@ -495,60 +491,60 @@ static int sync_fill_fence_info(struct fence *fence, void *data, int size) else info->status = 0; info->timestamp_ns = ktime_to_ns(fence->timestamp); - - return sizeof(*info); }

static long sync_file_ioctl_fence_info(struct sync_file *sync_file, unsigned long arg) { - struct sync_file_info *info; + struct sync_file_info info; + struct sync_fence_info *fence_info = NULL; __u32 size; - __u32 len = 0; int ret, i;

- if (copy_from_user(&size, (void __user *)arg, sizeof(size))) + if (copy_from_user(&info, (void __user *)arg, sizeof(info))) return -EFAULT;

- if (size < sizeof(struct sync_file_info)) - return -EINVAL; + /* + * Passing num_fences = 0 means that userspace doesn't want to + * retrieve any sync_fence_info. If num_fences = 0 we skip filling + * sync_fence_info and return the actual number of fences on + * info->num_fences. + */ + if (!info.num_fences) + goto no_fences;

- if (size > 4096) - size = 4096; + if (info.num_fences < sync_file->num_fences) + return -EINVAL;

- info = kzalloc(size, GFP_KERNEL); - if (!info) + size = sync_file->num_fences * sizeof(*fence_info); + fence_info = kzalloc(size, GFP_KERNEL); + if (!fence_info) return -ENOMEM;

- strlcpy(info->name, sync_file->name, sizeof(info->name)); - info->status = atomic_read(&sync_file->status); - if (info->status >= 0) - info->status = !info->status; + for (i = 0; i < sync_file->num_fences; ++i) + sync_fill_fence_info(sync_file->cbs[i].fence, &fence_info[i]);

- info->num_fences = sync_file->num_fences; - - len = sizeof(struct sync_file_info); - - for (i = 0; i < sync_file->num_fences; ++i) { - struct fence *fence = sync_file->cbs[i].fence; - - ret = sync_fill_fence_info(fence, (u8 *)info + len, size - len); - - if (ret < 0) - goto out; - - len += ret; + if (copy_to_user((void __user *)info.sync_fence_info, fence_info, + size)) { + ret = -EFAULT; + goto out; }

- info->len = len; +no_fences: + strlcpy(info.name, sync_file->name, sizeof(info.name)); + info.status = atomic_read(&sync_file->status); + if (info.status >= 0) + info.status = !info.status; + + info.num_fences = sync_file->num_fences;

- if (copy_to_user((void __user *)arg, info, len)) + if (copy_to_user((void __user *)arg, &info, sizeof(info))) ret = -EFAULT; else ret = 0;

out: - kfree(info); + kfree(fence_info);

return ret; } diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h index f0b41ce..a122bb5 100644 --- a/drivers/staging/android/uapi/sync.h +++ b/drivers/staging/android/uapi/sync.h @@ -42,21 +42,18 @@ struct sync_fence_info {

/** * struct sync_file_info - data returned from fence info ioctl - * @len: ioctl caller writes the size of the buffer its passing in. - * ioctl returns length of sync_file_info returned to - * userspace including pt_info. * @name: name of fence * @status: status of fence. 1: signaled 0:active <0:error * @num_fences number of fences in the sync_file - * @sync_fence_info: array of sync_fence_info for every fence in the sync_file + * @sync_fence_info: pointer to array of structs sync_fence_info with all + * fences in the sync_file */ struct sync_file_info { - __u32 len; char name[32]; __s32 status; __u32 num_fences;

- __u8 sync_fence_info[0]; + __u64 sync_fence_info; };

#define SYNC_IOC_MAGIC '>'

On 03/03/2016 11:40 AM, Gustavo Padovan wrote:

From: Gustavo Padovan gustavo.padovan@collabora.co.uk

Inform userspace how many fences are in the sync_fence_info field.

Signed-off-by: Gustavo Padovan gustavo.padovan@collabora.co.uk Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com

---

drivers/staging/android/sync.c | 2 ++ drivers/staging/android/uapi/sync.h | 2 ++ 2 files changed, 4 insertions(+)

diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c index 3a8f210..31aa462 100644 --- a/drivers/staging/android/sync.c +++ b/drivers/staging/android/sync.c @@ -525,6 +525,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file, if (info->status >= 0) info->status = !info->status;

• info->num_fences = sync_file->num_fences;

• len = sizeof(struct sync_file_info);

  for (i = 0; i < sync_file->num_fences; ++i) {

diff --git a/drivers/staging/android/uapi/sync.h b/drivers/staging/android/uapi/sync.h index a0cf357..4ffb7cc 100644 --- a/drivers/staging/android/uapi/sync.h +++ b/drivers/staging/android/uapi/sync.h @@ -47,12 +47,14 @@ struct sync_fence_info {

• userspace including pt_info.
  

• @name: name of fence
• @status: status of fence. 1: signaled 0:active <0:error

• • @num_fences number of fences in the sync_file
  • @sync_fence_info: array of sync_fence_info for every fence in the sync_file

  */ struct sync_file_info { __u32 len; char name[32]; __s32 status;

• __u32 num_fences;

  __u8 sync_fence_info[0]; };

Greg, this is ultimately your call. But to echo what I said before, I'm OK with the ABI break here if that's what's needed to get sync moved out of staging.

Pragmatically speaking, this won't break ordinary Android apps, because they don't get direct access to sync fence fds to begin with. Some privileged system processes do, but they go through libsync, which can be changed to deal with the ABI differences.

Anyway, for the whole series:

Acked-by: Greg Hackmann ghackmann@google.com